Supernova 2002ap in M74

Supernova 2002ap was discovered in M74 on January 29, 2002 by Japanese
amateur astronomer Yoji Hirose, 258" west and 108" south of the center of
that galaxy, at mag 14.5, rising a day later to 13.7, 13.4 on January 31,
12.5 on February 3, 12.4 on February 4, and eventually reached its maximum
brightness of 12.3 on February 12, 2002.

The type of this supernova has been preliminarily determined as type Ib/c,
a classification which was confirmed later. Its spectrum has shown
peculiar features; this has brought up evidence that this object was
perhaps a hypernova (super-luminous supernova, up to 100 times brighter
than "normal" supernovae of type Ia, occurring when very massive stars
explode at the end of their nuclear lives; the SN 2002ap progenitor star
has been estimated at at least 40 solar masses).

The image in this page was obtained on January 31, 2002 from Mt. Hopkins,
Arizona with the 1.2m telescope by Harvard CfA astronomers. Click to see
it compared to a Digital Sky Survey comparison image.

Radio radiation of the supernova was discovered very early, on February 1.
It will be most interesting to observe the development of this object at
all wavelengths. This supernova was definitely discovered before its maximum.
From February 5 to 12, it was observed at a maximal brightness of 12.3 mag,
then declined, thus less than might have been expected for a hypernova.
It was suspected that this object could be accompanied by a Gamma Ray
Burst .. this would have been by far the nearest such event observed yet.

As of late November 2002, SN 2002ap was still visible at about mag 18.7.
The last recorded magnitude determination was published for December 31, 2002
when it was estimated at magnitude 19.2.

Less than 1 1/2 year after this one, SN 2002ap, another supernova occurred in
the same galaxy, M74: SN 2003gd.